1. Field of the Invention
The present invention relates to an electronic musical instrument, a touch detection apparatus, a touch detecting method, and a storage medium.
2. Related Art
Velocity information indicative of the intensity of a sound generated by an electronic musical instrument such as an electronic piano has conventionally been detected as follows.
A first contact point and a second contact point are provided below each key of an electronic piano. The first and second contact points are turned on in positions in which a press amount (stroke) of the key differs from each other. A difference in time between on-timing of the first contact point and that of the second contact point is measured and velocity information is detected based on the resultant time difference. A musical sound of an intensity responsive to the velocity information is generated from a linked sound source.
An electronic piano such as one disclosed for example in Japanese Patent No. 3922225 has been put on the market in recent years that has three contact points below each key. This is intended to enable sound source control in the manner of damping of a piano with three contact points by adding one contact point in a position (intermediate stroke position) where a press amount becomes midway between those of conventional two contact points. For the convenience of description, these three contact points are called a first contact point, a second contact point, and a third contact point in the order in which a key is pressed down more deeply.
The aforementioned electronic piano with three contact points does not differ largely in structure from an electronic piano with two contact points in that velocity information is detected based on a difference in time between on-timing of the second contact point and that of the third contact point.
In the electronic piano with the three contact points, if the second contact is provided in a stroke position deeper than that of the conventional electronic piano with the two contact points, repetition action of a small amplitude in a deep stroke position can be detected like in an acoustic piano.
Like in the conventional electronic piano with two contact points, in the electronic piano with three contact points, timing of sound deadening is detected based on off-timing of the first contact point in a stroke position corresponding to a position in the conventional electronic piano. In the electronic piano with three contact points, sound deadening (turning on a damper) can be controlled using the first contact point and sound generation (touch strength and timing of starting sound generation) can be controlled using the second and third contact points.
Accordingly, if repetition of applying strokes continuously to the second and third contact points is made while the damper is off (released) in the electronic piano with three contact points, multiple musical sounds of the same pitch can be generated continuously and early. This enables reproduction of musical performance relating to repetition in the manner of an acoustic piano.
To achieve such performance relating to repetition, conventional two contact points should be increased to three contact points for one key. This involves many additional parts such as contacts (switches), interconnections, and diodes for a contact point matrix (switch matrix). This inevitably necessitates complication and cost increase. Hence, a conventional structure with only two contact points has been desired to achieve performance relating to repetition comparable to that achieved by an electronic piano with three contact points.